65523721 has 2 divisors, whose sum is σ = 65523722. Its totient is φ = 65523720.

The previous prime is 65523719. The next prime is 65523727. The reversal of 65523721 is 12732556.

65523721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65205625 + 318096 = 8075^2 + 564^2 .

It is a cyclic number.

It is not a de Polignac number, because 65523721 - 2¹ = 65523719 is a prime.

Together with 65523719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (65523727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32761860 + 32761861.

It is an arithmetic number, because the mean of its divisors is an integer number (32761861).

Almost surely, 2^65523721 is an apocalyptic number.

It is an amenable number.

65523721 is a deficient number, since it is larger than the sum of its proper divisors (1).

65523721 is an equidigital number, since it uses as much as digits as its factorization.

65523721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12600, while the sum is 31.

The square root of 65523721 is about 8094.6723837349. The cubic root of 65523721 is about 403.1495544285.

The spelling of 65523721 in words is "sixty-five million, five hundred twenty-three thousand, seven hundred twenty-one".